反应详情

A solution of 14.4 g. (0.12 mole) of 1-methylpyrrole-2-acetonitrile and 25 g. (0.12 mole) of p-trifluoromethylbenzoyl chloride in 120 ml. methylene chloride is chilled to -25° C. (external bath). Then 14 ml. (0.12 mole) stannic chloride is added dropwise over a half hour. The resultant suspension is permitted to come to room temperature and poured into ice-dilute hydrochloric acid. The aqueous phase is separated and washed successively with N,N-dimethyl-1,3-propane-diamine, 3N hydrochloric acid and a saturated solution of sodium chloride. The solvent is evaporated, and the product is isolated from the residual oil by column chromatography using acid-washed alumina. The solvents hexane, benzene, and ether are used as eluents. The first compound-bearing fraction not giving a positive Enrlich's test (in benzene) is collected. The solvent is evaporated and the resultant solid, 1-methyl-5-(p-trifluoromethylbenzoyl)-pyrrole-2-acetonitrile, in purified by recrystallization from isopropanol, m.p. 95-97.5° C.

1. customto come to room temperature
2. additionpoured into ice-dilute hydrochloric acid
3. customThe aqueous phase is separated
4. washwashed successively with N,N-dimethyl-1,3-propane-diamine, 3N hydrochloric acid
5. customThe solvent is evaporated
6. customthe product is isolated from the residual oil by column chromatography
7. washusing acid-washed alumina
8. customThe first compound-bearing fraction not giving a positive Enrlich's test (in benzene)
9. customis collected
10. customThe solvent is evaporated
11. customthe resultant solid, 1-methyl-5-(p-trifluoromethylbenzoyl)-pyrrole-2-acetonitrile, in purified by recrystallization from isopropanol, m.p. 95-97.5° C.